A shifting device for the powerless transmission of shift commands with a pivoted lever, which can be pivoted along a shift gate, wherein commands are transmitted to an automatic gear box by detection means for detecting the shift position, is known from the patent application DE 100 05 167 A1 (see also U.S. Pat. No. 6,662,924 which is hereby incorporated by reference). This is a shifting device in which a position of the gearshift lever is assigned to every individual gear, wherein the gearshift lever remains in the particular shift position and thus also sends a haptic feedback concerning the gear being selected to the driver.
Furthermore, a “shift by wire” shifting device is known from the patent application DE 197 56 034 A1, in which the gearshift lever is pivotable along a shift gate, and an inoperative position, into which the gearshift lever returns by itself from a deflected shift position, driven by a restoring force, is located between the shift positions, which are defined by shift stops.
In addition, reference is being made to the patent application DE 199 16 924 A1, which describes the basic function of an automatic shifting device. A selector lever is shown here, which can be moved along a shift gate for preselecting individual gears in two deflection directions and always returns by itself into the same starting position from the two deflection directions, wherein two different gears can be selected in at least one deflection direction of the selector lever by the selector lever being moved over a first section up to a first “stop” in the deflection direction for selecting a first gear, and the selector lever is moved over a second, longer section in the same deflection direction for selecting a second gear up to a second “stop,” while the first stop is pushed over. Since at least the particular first “stop” can be pushed over, it is not an actual stop in the original sense of this word, but only a perceptible intermediate position of the gearshift lever. The kinematic solution is, however, not disclosed in this document.
Consequently, the “shift by wire” shifting devices have essentially two embodiments, namely, shifting devices with fixed, stable gearshift lever positions and shifting devices with a single inoperative position and other unstable shift positions, into which the gearshift lever can be briefly deflected. Both variants have advantages and disadvantages. The current position of the transmission can be detected by feeling and can be seen at any time at the selector lever in shifting devices with fixed positions during normal operation, so that the driver is always informed of the current situation of the transmission. The mechanical connection with the transmission is absent in the “shift by wire” systems, and it is possible that the position of the selector lever does not agree with the position of the transmission, because certain positions of the gearshift lever or certain shift commands are not performed by the automatic transmission, because these may be interrupted by a logic verification in order to avoid unintended or destructive shifting actions.
Monostable shifting devices have no haptic feedback on the current position of the transmission, so that it is also impossible to transmit false information on the current shift position to the driver. In case of monostable shifting devices, the activation of a parking brake takes place in automatic transmissions mostly by means of an automatic switch, which is arranged, e.g., at the knob. A direct haptic feedback by the shifting device to the driver indicating that a certain situation of the transmission is present, e.g., that the parking brake is engaged, is not known, so that misunderstandings may occur, for example, concerning a key lock.